P0087 fuel rail pressure low limp under high loads

[richp]

Hi,

Just returned to Illinois from Quartzsite towing the fiver. I have122k miles on an '09 LMM. No problems going down in January, but several 0087 episodes on return last week. Absolutely stock truck with auxiliary filtration and regular Power Service throughout its life. Regular filter changes. Regular Chevy dealer service at the same competent location. No lift pump (duly noted, John).

Obviously, working through this thread gives possible short and long term answers. But my solution for getting home the last 1,000 miles -- starting in western Oklahoma -- was to keep post turbo EGT's in the 1,000 degree range, and never more than 1,100. I used that as a proxy for the temps the injectors and incoming fuel were experiencing. I did this by doing a lot of manual gear selection on hills. I recall only one post in this entire thread that mentions that approach. Hmmm.

I will figure out my future with this truck somehow. But when other brands of diesels are notable for much longer injector life, it makes me wonder what GM has stuck us lifelong, committed customers with.

FWIW.

[richp]

Hi,

My dealer had it for two days, and as I expected, found nothing wrong -- injectors test solid, no codes left, and absent the load from towing heavy, on hills, while hot, no way to get their equipment to register my issue. They report all fuel lines solid, the fuel cooler clean, and no leaks anywhere.

These are two guys who know the truck since new, have serviced it thoroughly and regularly, and otherwise have my confidence. So for now I'm going to drive on and see what the future holds.

They did offer a thought that freeing up the exhaust might help keep overall temps down and thus keep the returned fuel cooler. Coming from a dealership, I found that interesting. Any thoughts on that from anyone?

[CoyleJR]

Hi Rich,

I agree with the dealer that opening up the exhaust would help cool the motor by lowering the EGT a little. I do not think it will get you a substantial drop in fuel temperature. Additionally, the noise caused by most large exhaust systems will make for a very long trip from Illinois to Arizona next year.

My post about the P0087 code was the one posted just before your post (take a look). If I keep plenty of fuel in my fuel tank it seems to cool the returning hot fuel and stop the P0087 problem. When your truck threw the p0087 code did you have over half a tank of fuel? I think a second fuel cooler would cool the returning hot fuel a lot better than a larger exhaust system. Just my thoughts on the P0087 code.

Good luck
John

[richp]

Hi John,

Thanks for the response.

I usually fill up at the end of the day's run with the fiver, so I can get a fast start in the morning. And I have been getting a few hours of clean performance -- until the tank is lower and the day is warmer. So refueling more often might help, although it would slow the day's progress.

I have pondered adding another cooler. Insofar as I recall, nobody in this thread has mentioned actually doing it, or a supplier with suitable hardware. So that is an option with dangling questions...

And yeah, the exhaust noise issue has occurred to me, and would be a turnoff. In addition to my own objection, I might never get Maureen to ride with me again. A very last resort, I think.

I appreciate being able to add your thoughts to the mix.

[Inspector]

Lets talk about the L5P for a second. Recently I have been shown the CEL and the Idash calls out a code for the MAP sensor along with a reduced engine power msg but doesn't set a code for that. I could clear the check engine but the "Power will be reduced in 175 miles" msg would persist. I spoke with Banks tech thinking that the harness from the Derringer to the Map sensor was or the connector to Map might be the problem I was told to disconnect the Banks connector form the Map and connect the OEM connector and see if the code returned. What happened was and almost immediate it went to limp and 15 miles an hour max. The Idash now thru another code for the first time, P0191 which is the fuel rail pressure sensor A circuit not valid. the sensor is a duel unit. I replaced the sensor and everybody is happy. The hard part was I don't trust the Chinisium stuff or Amazon so to the dealer I went and left with a new OEM sensor and 250.00 dollars lighter. And after all that it was manufactured in Thailand. Lord have mercy

[arveetek]

The hard part was I don't trust the Chinisium stuff or Amazon so to the dealer I went and left with a new OEM sensor and 250.00 dollars lighter. And after all that it was manufactured in Thailand. Lord have mercy

It is SO, SO difficult to locate and purchase quality parts these days. I won't hardly buy anything at an auto parts store (except oil and consumables), since the majority of parts there will be manufactured by the lowest bidder. Most of the time I will buy "OEM" parts from Rock Auto when I can, but even then (as you found out), OEM parts aren't necessarily made where you hoped they would be.

For example, genuine BOSCH injectors for the 6.5L used to be sourced only from Germany, but often now they are made in India. *sigh*

Casey